1. Field of the Invention
The present invention relates to elements which comfort, protect, and maintain the foot of the wearer within articles of athletic footwear, including sports shoes and boots, for example, ski boots or mountain boots, and especially those which have a rigid shell.
More particularly, the present invention is directed to a removable protective element for covering, at least partially, a liner for an athletic shoe or boot, and to a liner adapted to receive the removable protective element.
2. Description of Background and Relevant Information
There are many types of athletic footwear, such as ski boots and ice skates, where it is necessary as a matter of function to securely maintain the foot in a desired position within a shoe or boot. This is necessary because excessive movement of the foot independent of movement of the article of footwear can significantly detract from the responsiveness of the footwear, impairing the wearer's ability to perform skillfully and even posing a possible health hazard. Examples of elements used to accomplish this include internal liners, rear wedges, front tongues, and other accessories.
At the same time, it is necessary to provide a comfortable environment for the foot, both to avoid compromising the wearer's ability to enjoy the sport in question, and to prevent surface trauma to the foot such as blisters and subsurface trauma such as cramping and sprains.
As may be seen, the function of maintaining the foot securely in place in the boot or shoe is distinct from the function of providing comfort and protection to the foot. This distinction is reflected in differences in the materials appropriate to each; in order to maintain the foot in place, a relatively firm or semi-rigid structure is most appropriate, whereas comfort and protection are better served by a relatively soft or resilient structure.
The elements currently used in athletic footwear to accomplish these ends accordingly consist of two main portions. The first portion is composed of a relatively rigid, dense material that conserves its functional shape, serving primarily to hold the foot in a given position within the shoe or boot. In the case of an internal liner, this material takes the shape of a sock-shaped envelope designed to hold the foot. The second portion is composed of relatively soft paddings or coverings that aim to avoid, at least at critical locations, excessive contact pressures between the foot and the liner and/or the outer shell of the shoe or boot.
The need to combine these two portions in a single element, in order to obtain both secure placement and comfort of the foot, is reflected in the form of superpositions. The base for these superpositions is a relatively rigid envelope having a cavity that conforms closely to the shape of the foot and which is sufficiently dense to ensures mechanical retention of the foot in a given position. Over this envelope is superimposed a covering made out of a material which is softer and more resilient, to ensure the comfort of the foot.
The assembly of this covering to the envelope is normally done in a permanent manner, as by gluing or stitching. This poses compatibility problems between the various materials utilized, and those problems are complicated by the desire to fulfill overall design goals such as reducing the cost of manufacture, utilizing specific materials, and minimizing the complexity of assembly.
Furthermore, the elements used to comfort, protect, and maintain the foot are subject to wear. In particular, the soft coverings, and especially those portions positioned adjacent the top of the upper of the shoe or boot, are subject to wear and soiling due to repeated putting on and taking off of the boot.
It has been attempted, in the context of a rear wedge, to protect the soft covering at these critical locations using a skin which is both flexible and resistant to the above cited attacks. This attempt involved providing, for attachment on the vulnerable areas of the semi-rigid portion of the liner, a protective cover composed of a soft covering for comfort, and a protective skin capable of folding down on itself, at least partially, through elastic deformation, around the semi-rigid portion. However, this protective cover still remains permanently attached to the semi-rigid portion of the liner by traditional means such as sewing or gluing over substantial lengths or surfaces. This remedy to the disadvantages cited above only delays degradation due to wear because it is the fixed protective cover which will undergo these degradations, a protective cover which can only be replaced by replacing the liner in its entirety.